by Dinesh Thakur Category: Servlet with MySql Database

This Function will Returns the largest integer value that is not Greater than passed numeric expression.

First i made a database named 'dbase' within the reference of mySql(php myAdmin). Then i import all the required java package from java library according to  need of program. Then i made a class named 'MySqlFLOORFunction' which extends 'HTTPSERVLET' completely. Then after i use service()Method that will bring the request from doGet()Method for output on the web browser.

Then after i loaded al the required drivers for database accessing. Here i declare variables for next use of program i declare 'connection' that will use to create a link between the database and the java code. Here i use 'resultSet' that will use to get the value from the selected columns and the rows. At the last instance of declaring variable i use 'preparedStatement' that will use to executing the selected Query like executeQuery as (Select FLOOR('8.69')). I use doGet()Method for output on web browser.

I use 'HTML' coding and some tags to present the output on the web browser in tabular form.

import java.io.IOException;

import java.io.PrintWriter;
import java.sql.DriverManager;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class MySqlFLOORFunction extends HttpServlet
 {
      public void service(HttpServletRequest rq, HttpServletResponse rp)throws IOException, ServletException
        {
            rp.setContentType("text/html");
            PrintWriter disp = rp.getWriter();
            String driver = "com.mysql.jdbc.Driver";
            String url = "jdbc:mysql://localhost/dbase";
            String uid = "root";
            String psw = "root";
            Connection con=null;
            PreparedStatement ps = null;
            ResultSet rs;
            try
             {
                  Class.forName(driver);
                  con = DriverManager.getConnection(url,uid,psw);
                  ps=con.prepareStatement("Select FLOOR('8.69')");
                  rs = ps.executeQuery();
               String title = "Using FLOOR Function";
                 String docType ="<!doctype html public \"-//w3c//dtd html 4.0 " + "transitional//en\">\n";
              disp.println(docType + "<html>\n" + "<head><title>" + title + "</title></head>\n" +
                 "<body bgcolor=\"#f4efef\">\n" + "<h1 align=\"center\">" + title + "</h1>\n" + "<ul>\n" +
              "<table width=\"50%\" border=\"1\" align=\"center\">\n" + "<th>Value</th>\n"+ "</body> </html>");
                while(rs.next())
                     {
                          String val = rs.getString(1);
                       disp.println("<tr><td align=\"center\">" + val +"</td></tr>" );  
                     }     
             }        
                       catch(Exception e) 
                         {
                                e.printStackTrace();
                         }
                                disp.close();
      }
                                  public void doPost(HttpServletRequest rq,HttpServletResponse rp)throws IOException,ServletException
                                    {
                                       doGet(rq,rp);
                                    }
 }
Web.xml
 
<servlet>
   <servlet-name>MySqlFLOORFunction</servlet-name>
   <servlet-class>MySqlFLOORFunction</servlet-class>
</servlet>
<!-- servlet mapping -->
<servlet-mapping>
   <servlet-name>MySqlFLOORFunction</servlet-name>
   <url-pattern>/MySqlFLOORFunction</url-pattern>
</servlet-mapping>




About Dinesh Thakur

Dinesh ThakurDinesh Thakur holds an B.SC (Computer Science), MCSE, MCDBA, CCNA, CCNP, A+, SCJP certifications. Dinesh authors the hugely popular blog. Where he writes how-to guides around Computer fundamental , computer software, Computer programming, and web apps. For any type of query or something that you think is missing, please feel free to Contact us.



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